 <style>
        :root {
            --primary: #136195;
            --primary-dark: #0a4970;
            --secondary: #2D7173;
            --secondary-dark: #1d5557;
            --accent: #34495e;
            --accent-dark: #263445;
            --success: #008a5e;
            --success-dark: #006a46;
            --warning: #d35400;
            --danger: #c0392b;
            --light: #f8f9fa;
            --dark: #343a40;
            --gray: #6c757d;
            --white: #ffffff;
            --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
            --transition: all 0.3s ease;
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background-color: #f5f7fa;
            color: #333;
            line-height: 1.6;
        }

        .container {
            width: 100%;
            max-width: 1320px;
            margin: 0 auto;
            padding: 0 20px;
        }

        /* Header */
        header {
            background: linear-gradient(135deg, var(--primary), var(--primary-dark));
            color: white;
            padding: 1.5rem 0;
            box-shadow: var(--shadow);
        }

        .header-content {
            display: flex;
            justify-content: center;
            align-items: center;
            text-align: center;
        }

        .logo {
            font-size: 1.8rem;
            font-weight: 700;
            letter-spacing: 1px;
        }

        /* Buttons */
        .btn {
            display: inline-block;
            padding: 0.75rem 1.5rem;
            border-radius: 50px;
            text-decoration: none;
            font-weight: 600;
            letter-spacing: 0.5px;
            transition: var(--transition);
            border: none;
            cursor: pointer;
            text-align: center;
        }

        .btn-primary {
            background-color: var(--primary);
            color: white;
            box-shadow: 0 4px 15px rgba(19, 97, 149, 0.2);
        }

        .btn-primary:hover {
            background-color: var(--primary-dark);
            transform: translateY(-2px);
            box-shadow: 0 6px 20px rgba(19, 97, 149, 0.3);
        }

        .btn-secondary {
            background-color: var(--secondary);
            color: white;
            box-shadow: 0 4px 15px rgba(45, 113, 115, 0.2);
        }

        .btn-secondary:hover {
            background-color: var(--secondary-dark);
            transform: translateY(-2px);
            box-shadow: 0 6px 20px rgba(45, 113, 115, 0.3);
        }

        .btn-accent {
            background-color: var(--accent);
            color: white;
            box-shadow: 0 4px 15px rgba(52, 73, 94, 0.2);
        }

        .btn-accent:hover {
            background-color: var(--accent-dark);
            transform: translateY(-2px);
            box-shadow: 0 6px 20px rgba(52, 73, 94, 0.3);
        }

        .btn-success {
            background-color: var(--success);
            color: white;
            box-shadow: 0 4px 15px rgba(0, 138, 94, 0.2);
        }

        .btn-success:hover {
            background-color: var(--success-dark);
            transform: translateY(-2px);
            box-shadow: 0 6px 20px rgba(0, 138, 94, 0.3);
        }

        .btn-outline {
            background-color: transparent;
            color: white;
            border: 2px solid white;
        }

        .btn-outline:hover {
            background-color: white;
            color: var(--primary);
            transform: translateY(-2px);
        }

        /* Back button */
        .back-button {
            display: inline-block;
            margin: 1rem 0;
            padding: 0.75rem 1.5rem;
            background-color: var(--primary);
            color: white;
            text-decoration: none;
            border-radius: 50px;
            font-weight: 600;
            transition: var(--transition);
            box-shadow: var(--shadow);
        }

        .back-button:hover {
            background-color: var(--primary-dark);
            transform: translateY(-2px);
            box-shadow: 0 6px 20px rgba(19, 97, 149, 0.3);
        }

        .back-button i {
            margin-right: 0.5rem;
        }

		/* Modal */
        .modal {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-color: rgba(0, 0, 0, 0.5);
            display: flex;
            align-items: center;
            justify-content: center;
            z-index: 2000;
            opacity: 0;
            visibility: hidden;
            transition: var(--transition);
        }

        .modal.open {
            opacity: 1;
            visibility: visible;
        }

        .modal-content {
            background-color: white;
            border-radius: 12px;
            width: 100%;
            max-width: 600px;
            padding: 2rem;
            position: relative;
            transform: translateY(20px);
            transition: transform 0.3s ease;
        }

        .modal.open .modal-content {
            transform: translateY(0);
        }

        .modal-close {
            position: absolute;
            top: 1rem;
            right: 1rem;
            background: none;
            border: none;
            font-size: 1.5rem;
            cursor: pointer;
            color: var(--gray);
            transition: var(--transition);
        }

        .modal-close:hover {
            color: var(--danger);
        }

        .modal-title {
            font-size: 1.5rem;
            margin-bottom: 1rem;
        }

        .modal-body {
            margin-bottom: 1.5rem;
        }

        .modal-footer {
            display: flex;
            justify-content: flex-end;
            gap: 1rem;
        }

        /* Search */
        .search-container {
            background-color: white;
            padding: 1.5rem;
            border-radius: 8px;
            box-shadow: var(--shadow);
            margin-top: 1.5rem;
            position: relative;
            z-index: 10;
        }

        .search-form {
            display: flex;
            gap: 1rem;
        }

        .search-input {
            flex: 1;
            padding: 0.75rem 1.25rem;
            border: 1px solid #e1e5e9;
            border-radius: 50px;
            font-size: 1rem;
            transition: var(--transition);
        }

        .search-input:focus {
            outline: none;
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(19, 97, 149, 0.2);
        }

        /* Main content */
        .main-content {
            padding: 2rem 0 4rem;
        }

        .section-heading {
            text-align: center;
            margin-bottom: 3rem;
        }

        .section-heading h2 {
            font-size: 2.2rem;
            margin-bottom: 1rem;
            color: var(--dark);
        }

        .section-heading p {
            color: var(--gray);
            max-width: 700px;
            margin: 0 auto;
        }

        /* Material Cards */
        .materials-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
            gap: 2rem;
        }

        .material-card {
            background-color: white;
            border-radius: 12px;
            overflow: hidden;
            box-shadow: var(--shadow);
            transition: var(--transition);
            display: flex;
            flex-direction: column;
            height: 100%;
        }

        .material-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 20px rgba(0, 0, 0, 0.12);
        }

        .material-card-header {
            background-color: var(--primary);
            color: white;
            padding: 1.5rem;
            position: relative;
        }

        .material-card-header.green {
            background-color: var(--success);
        }

        .material-card-header.blue {
            background-color: var(--secondary);
        }

        .material-card-header.dark {
            background-color: var(--accent);
        }

        .material-card-header.danger {
            background-color: var(--danger);
        }

        .material-card-title {
            font-size: 1.5rem;
            font-weight: 700;
            margin-bottom: 0.5rem;
        }

        .material-card-description {
            font-size: 0.9rem;
            opacity: 0.9;
        }

        .material-card-icon {
            position: absolute;
            top: 1.5rem;
            right: 1.5rem;
            font-size: 1.8rem;
            opacity: 0.5;
        }

        .material-card-body {
            padding: 1.5rem;
            flex-grow: 1;
            display: flex;
            flex-direction: column;
        }

        .material-links {
            margin-top: 1rem;
            display: flex;
            flex-direction: column;
            gap: 0.75rem;
        }

        .material-link {
            display: flex;
            align-items: center;
            gap: 0.75rem;
            padding: 0.75rem;
            background-color: #f8f9fa;
            border-radius: 8px;
            text-decoration: none;
            color: var(--dark);
            transition: var(--transition);
        }

        .material-link:hover {
            background-color: #e9ecef;
            transform: translateY(-2px);
        }

        .material-link-icon {
            display: flex;
            align-items: center;
            justify-content: center;
            width: 36px;
            height: 36px;
            background-color: var(--primary);
            color: white;
            border-radius: 8px;
            font-size: 1rem;
        }

        .material-link-icon.pdf {
            background-color: #e74c3c;
        }

        .material-link-icon.video {
            background-color: #e67e22;
        }

        .material-link-icon.exercise {
            background-color: #3498db;
        }

        .material-link-icon.link {
            background-color: #9b59b6;
        }

        .material-link-icon.quiz {
            background-color: #2ecc71;
        }

        .material-section {
            margin-top: 1.5rem;
        }

        .material-section:first-child {
            margin-top: 0;
        }

        .material-section-title {
            font-weight: 600;
            font-size: 1rem;
            margin-bottom: 0.75rem;
            color: var(--gray);
            border-bottom: 1px solid #e9ecef;
            padding-bottom: 0.5rem;
        }

        /* Footer */
        footer {
            background-color: #2c3e50;
            color: white;
            padding: 1.5rem 0;
            text-align: center;
        }

        /* Back to top button */
        .back-to-top {
            position: fixed;
            bottom: 2rem;
            right: 2rem;
            width: 50px;
            height: 50px;
            border-radius: 50%;
            background-color: var(--primary);
            color: white;
            display: flex;
            align-items: center;
            justify-content: center;
            text-decoration: none;
            font-size: 1.25rem;
            box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
            transition: var(--transition);
            opacity: 0;
            visibility: hidden;
            z-index: 1000;
        }

        .back-to-top.show {
            opacity: 1;
            visibility: visible;
        }

        .back-to-top:hover {
            background-color: var(--primary-dark);
            transform: translateY(-5px);
        }

        /* Responsive */
        @media (max-width: 991px) {
            .materials-grid {
                grid-template-columns: repeat(2, 1fr);
            }
        }

        @media (max-width: 767px) {
            .materials-grid {
                grid-template-columns: 1fr;
            }

            .search-form {
                flex-direction: column;
            }
        }
    </style>